[PATCH] add return value checking of get_user() in set_vesa_blanking()

[akpm@osdl.org: bugfix]
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 75ff028..a8239da 100644 (file)
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -152,7 +152,7 @@ static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 static void save_cur(struct vc_data *vc);
 static void reset_terminal(struct vc_data *vc, int do_clear);
 static void con_flush_chars(struct tty_struct *tty);
-static void set_vesa_blanking(char __user *p);
+static int set_vesa_blanking(char __user *p);
 static void set_cursor(struct vc_data *vc);
 static void hide_cursor(struct vc_data *vc);
 static void console_callback(struct work_struct *ignored);
@@ -2369,7 +2369,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
                        ret = __put_user(data, p);
                        break;
                case TIOCL_SETVESABLANK:
-                       set_vesa_blanking(p);
+                       ret = set_vesa_blanking(p);
                        break;
                case TIOCL_GETKMSGREDIRECT:
                        data = kmsg_redirect;
@@ -3313,11 +3313,15 @@ postcore_initcall(vtconsole_class_init);
  *     Screen blanking
  */
 
-static void set_vesa_blanking(char __user *p)
+static int set_vesa_blanking(char __user *p)
 {
-    unsigned int mode;
-    get_user(mode, p + 1);
-    vesa_blank_mode = (mode < 4) ? mode : 0;
+       unsigned int mode;
+
+       if (get_user(mode, p + 1))
+               return -EFAULT;
+
+       vesa_blank_mode = (mode < 4) ? mode : 0;
+       return 0;
 }
 
 void do_blank_screen(int entering_gfx)